Nigericin help

I have read conflicting information regarding the effects of nigericin
on live cells in normal physiologic media: (1) Dissipates _membrane
potential_ only, while not disrupting active transport or other
physiologic activities OR (2) Dissipates _pH gradient_ in addition to
potential and affects all cellular processes. Again, this is under
normal conditions, not as a tool to make a standard curve for
intracellular pH measurements. My ultimate goal is to dissipate or
equilibrate the pH gradient OR the membrane potential across the
plasma membrane and then measure uptake of a compound. Any help would
be appreciated,
James Martiney, Ph.D.
sherry.lab at picower.edu